Minimal, battery-optimized ambient noise app for focus, sleep, and relaxation.
Open source, privacy-first, and works fully offline.
Generate 9 different types of noise on your Android device—no ads, no tracking, no login, no network required.
ChromaTone generates nine scientifically recognized types of noise for different needs:
- White Noise (FOCUS): Balanced across all frequencies, ideal for masking distractions.
- Pink Noise (RELAX): More energy in lower frequencies, great for gentle relaxation.
- Brown Noise (SLEEP): Deep, low-frequency sound, perfect for deep sleep.
- Blue Noise (REST): Higher energy in upper frequencies, for alertness and clarity.
- Green Noise (CREATE): Mid-frequency emphasis, for creative focus.
- Violet Noise (STUDY): Highest-frequency, subtle sound, for study and concentration.
- Grey Noise (CALM): Perceptually balanced across the human hearing range.
- Azure Noise (BRIGHT): Sharp high-frequency emphasis for intense focus.
- Red Noise (HEAVY): Deepest bass profile for industrial-grade masking.
All noise is generated on-device for maximum privacy, battery efficiency, and performance. ChromaTone is designed for Android, works fully offline, and never collects or shares your data.
- Go to Releases and download the latest
app-release.apk. - Transfer to your Android device and install. (You may need to allow installs from unknown sources.)
- Clone the repository:
git clone https://github.com/surendranb/chromatone.git cd chromatone - Open in Android Studio (Giraffe or newer recommended).
- Build & Run:
- Connect your Android device (minSdk 26, Android 8.0+)
- Click 'Run'
▶️ in Android Studio, or use the emulator.
- Minimal UI: No clutter, just the essentials for quick access. 3x3 high-signal grid for muscle memory.
- System Theme Sync: Automatically follows your device's Dark or Light mode with a neutral, non-intrusive palette.
- Timer: Set a sleep or focus timer with a single slider. Countdown is always visible.
- Background Playback: Audio continues even when the app is in the background.
- Battery Optimized: Uses Android's foreground service for efficient playback and minimal battery drain.
- No Ads, No Tracking: No analytics, no network calls, no data collection—ever.
- Tiny APK: Under 5MB, fast to install and update.
- Works Offline: All noise is generated locally, no internet required.
- No Account Needed: No logins, no personal data.
- Device Optimized: Runs smoothly on all modern Android devices, including low-end phones.
- No permissions except audio, notifications, and backup.
- No analytics, tracking, or network code.
- No data leaves your device.
- Open source: Review the code any time.
- Additional ambient sounds: rain, ocean, wind, forest, and more
- Customizable sound mixes (combine multiple noise types or ambient sounds)
- Widget for quick access from home screen
- Scheduling (auto start/stop at set times)
- Android Auto and Wear OS support
- User feedback-driven improvements
Contributions are welcome! Please open an issue or pull request for bug fixes, features, or suggestions.
MIT License. See LICENSE for details.
- If you can't install the APK, check your device's security settings for 'Install unknown apps.'
- For build issues, ensure you have the latest Android Studio and SDK tools.